Wave inverter



D. L.H

March 13, 1951 y INVENTOR Donald HMT BY l; l Q//rToRNEYSM by the reference'character 29.

The automatic y constant, for example, in the order of one-quarter second. The resistor 31 which inter-connects the control grid 33 and the automatic control Volume 29 is a grid resistor. The amplitude of the voltage of the secondary carrier source expands and contracts under the action of the automatic volume control which is responsive to the pri- Y 34 is by-passed to the cathode for radio frequency through a by-pass condenser 36. The suppressor grid 35 is directly connected to the cathode 32 of the amplifier tube. The square wave voltage Supplied by the square wave generator 38 is preferably amplied and regulated by the automatic volume control circuit 29 tol a voltage which is slightly greater than the maximuml amplitude of the modulated primary carrier Wave which is impressed upon the transformer I0. The resistor 45 is a screen dropping resistor and is connected to the high voltage source 43. The plate 3| of theramplier tube 33 is connected to the upper end of a primary winding 4I ofk a coupling transformer 45. The lower end of the primary winding is connected to ground for carrier wave frequency through the coupling condenser 44.

I provide for subtracting the voltage of the modulated carrier wave inthe transformer I9 from the secondary carrier wave Voltage in the transformer 4U by means of va duo-diode rectifier 2!! having a detecting circuit, whereby the resultant Voltage generates a wave such as shown in Figure 5 of the drawing. The duo-diode rectifier 20 comprises two plates 2I and 22 and two cathodes 23 and 24. The plate 22 and the cathode 23 are connected to the upper terminal I5 of the secondary winding I3 of the transformer I9. The plate 2I is connected to the upper terminal I1 of the secondary winding 42 of the transformer 40. to the lower terminal I8 of the secondary winding 42 of the coupling transformerV 4U. Connected in parallel across the secondary winding 42 is an adjustable balancing resistor 4S. Connected in parallel with the balancing resistor 4G are two condensers 25 and 2E connected in series with respect to each other. The lower terminal I3 of the secondary Winding I3 of the transformer I is connected to a tap 21 which is intermediate the two condensers 25 and 2B. The resultant voltage from the tube 20 appears across the two conductors I) and 5I. Theresistor 41 is a detector load resistor for the high impedance path of the detector circuit. The resultant output voltage is supplied to a series resonant circuit comprising an inductance 48 and a condenser 49 which is tuned substantially to resonance at a frequency substantially equal to the frequency of the secondary carrier wave source from the square wave generator 38. The output resultant voltage appears across the conductors 52 and 53 and is shown by the wave form of Figure 5. The secondary winding 42 is a low impedance winding, and the condenser 49 is a loW impedance condenser. The condensers 25 and 26 by-pass the frequency of the primary carrier wave source and form the return circuit for thetwo diodes of the tube 20 to ground.

The cathode 24 is connectedV 4, The duo-diode tube 20 operates as a gate detector and alternately is rendered conducting by one square Wave potential across the secondary 42 of the transformer 40 and rendered non-conducting by the opposite square wave potential. When the tube 20 is rendered conducting, a subtraction operation takes place which subtracts the carrier Wave voltage in the primary source of the transformer I0 from the carrier wave voltage in the transformer 4B. When the tube becomes conducting, a resultant carrier wave voltage appears across the conductors 5E) and 5 I which voltage, when applied to the series resonant circuit 48 and 49, produces a voltage across the condenser 49 which may be represented by the curve in Figure 5.

My detector circuit comprises two halves, one for each of the half cycles of the carrier wave source. For one of the half cycles of the carrier `wave source, the detector circuit may be traced as follows: beginning with the adjustable pointer 54, the circuit extends through the upper half of the resistor 46, the plate 2| and the cathode 23 ofthe tube 20, the resonant circuit including the condenser I4 and the secondary winding I3 of the transformer I0; and the combination of the load resistor 41, the output load condenser 49 and the inductance 48 which is connected to the adjustable pointer 54. For the other half cycle of the carrier wave source, the detector circuit may be traced as follows: beginning at the ad justable pointer 54, the circuit extends through the lower half of the resistor 46, the cathode 24 and the plate 22 of the tube 23, the resonant circuit including the condenser I4 and the secondary winding I3 of the transformer I9, and the combination of the load resistor 41, the output lead condenser 49, and the inductance element 48 which is connected to the adjustable pointer 5t. Inasm'uch as the detector circuits traced above have voltages therein both from the primary carthe primary input carrier wave frequencies arel 'Dy-passed to ground through the condensers 25 and 26 respectively. The secondary winding 42 Ifor the transformer 46 is untuned and represents a lowimpedance for high frequencies such as for the frequencies of both the primary'carrier wave source `and the secondary carrier wave circuit having a low impedance to the secondary v carrier wave energy. The peak power of the sec-` impedance to the incoming primary carrier wave.

frequency.k However, the circuit comprising the secondary winding I3 and the condenser I4 is not resonant to the frequency of the secondary source from the square wave generator 38 and thus rep-r resents a low impedance to the secondary carrierv wave frequency. The condenser 49 and the inductance element 48Vare tuned substantially to resonance at a frequency of the secondary carrier wave source and thus represent a series resonant ondary.- carrier Wave source is thusi-nctinlluenced bythe primary. carrier. Wave.; source For a are: determined setting ofthe automatic volume: control circuit 29 the voltageof the secondary source is maintained relatively- .constant and; this relatively constant voltage is; substantially unaffected by the modulatign orpeak noises appearingY in the; primary carrier wave source applied to the transformer lli. This substantially non-interference action. appears to result from thefact that the secondary Windingk 42 represents a low impedanceto the incomingv primary carrier wave frequency in the-transformer Il); plus the fact that the secondary winding l,3 and the condenser I4 represent a low impedancev to the frequency of the secondary carrier wave. source. In other words, the voltage of the primary carrier wave source andthe voltageof the-secondary carrier wave,A source may beA characterizedl as being both solid or stable and thus the detector tube 20, whichl is subjected to both of these voltages, detects, gates and limits the differential voltages of the two carrier wave sources, including the spurious interference .waves as shown in Figure 2 which have an amplitudegreater than the amplitude of the modulated carrier wave source. The spurious interference wave peaks are, however, limited by the. amplitude of the secondary carrier wave source, such as shown in Figure 4 which represents a theoretical illustration of the detecting, gating and limiting action of the tube. The wave as shown in Figure 5 is the actual'wave and represents the voltage as one can discern upon an oscilloscope with the terminals connected across the output conductors 5I and 53. rll'ie upper half and the lower h alfi of Figure 5 representtheenergy detectedgated Vand limited by thetwodetector circuits hereinbefore traced, In Figure 5ituis observed thatv the ,noise energy, so to speak, cuts a slot or depression as at 55 into the upper and lower envelopesiof Figure 5. From the standpoint of ordinaryl reception, the two slots or depressions 55 are directlyoppositeifrom each other and of equal value, so that, when the envelope is received upon a receiver, the operator or the listener cannot hear any appreciable noise disturbance to distort the intelligence. Thus, in my invention, the spurious"interferencewave energies as found in ordinary reception are limited and inverted, so that in my circuit the intelligence controls the noise, instead of the noise controlling the intelligence.

Although I have shown and described my invention with a certain degree of particularity, it is understood that changes may be made therein without departing from the spirit of the invention which are included within the scope of the claims hereinafter set forth. 1

I claim as my invention:

l. A wave inverter system comprising, in combination, a first transformer adapted to be energized by a primary modulated carrier wave source, said transformer having a secondary winding, a condenser connected across the secondary winding and forming a resonantcircuit tuned substane tially to resonance at a frequency equal to the frequency of the primary carrier wave source, a second transformer adapted to be energized by a secondary carrier wave source having a frequency less than the frequency of the primary carrier wave source, said second transformer having a secondary Winding representing a low impedance for the frequencies of both the primary and the secondary carrier wave sources, the secondary winding of the rst transformer and the conde nglgwhich is, elinected therfacross representinsta .low impedance.1 to.- the secondary carrier wave, a diode detector having a, detector circuit connectedbetween the-:secondary winding of the first transformer and. the.` secondary Winding of the second,V transformer, circuit means for sausing saidsecondary carrier wave. source to alternately render said diode detector conducting and non-conducting at the frequency of said secondaryv carrier. wave, said ,diode detector detecting, gating and limiting the differential` Voltage between the two carrier wave sources when said diode detector is rendered conductingan output circuit including at least a condenser connected in the. detector circuit of the diode detector, and means respons-ivetothe power of the primary carrier wave source for varying. the amplitude of the secondary carrier wave source.

' 2. A- wave.inverter'systemcomprising in combination, agfirsttransformer adapted to be energizedby a primarymodulated carrier wave source, said transformerhaving asecondary winding, a condenser connected across the secondary winding-and forming a resonant circuit tuned substantially to resonance at a. frequency equal to the frequency ofv the 1 primary carrier'` Wave source, a second transformer adapted to be energized by a secondary carrierv wave source having a frequency lessthan theffrequencyy ofthe primary wave source, said. second. transformer having a secondary. winding representing a W; impedance for the. frequencies of both` the primary and the secondary carrier wave sources, theV secondary windingvof the vfirst.transformer and the condenserwhich; isA connected` there-across representinga low; impedance to f thefsecondary carrier Wave, a diodedetector; havinga detector circuit connected betweenH the secondary Winding of the, first .transformer rand the secondary winding of the second transformer, circuit means for causing saidsecondary carrier wave source to alternatelyY render saiddiode detector conducting and non-conductingl at the frequency of said secondaryj carrierr wave said diode detector detecting,` gating andlimiting the differential voltagebetween the tWo carrier Wave sources when said dioden detector is rendered conducting, an output circuit; includingz'at least a condenser connected in the detector circuit of the diode detector, and means responsive to the power of the primary carrier wave source for varying the amplitude of the secondary carrier wave source, said secondary carrier Wave source comprising a square top wave.

3. A communication system including carrier wave input means having first and second ends, a source of injected waves having a greater maximum amplitude and a lower frequency than said carrier Waves, injector input means for said injected waves, said injector input means having first and second ends, first rectifier means having first electron emitting means and first electron receiving means, second rectifier means having second electron emitting means and second electron receiving means, output circuit means connected between said second end of said carrier wave input means and said second electron receiving means, means for connecting said nrst end of said carrier wave input means to both said first electron receiving means and to said second electron emitting means, means for connecting said second electron receiving means and said first electron emitting means, respectively, to said first and second ends of said injector input means, and carrier Wave bypass means for con- 7 necting said first and second ends of said injector input means to said second end of said carrier Wave input means.

4. A communication system including, a source of modulated carrier waves, antiresonant input means for said modulated carrier waves, said antiresonant input means having rst and second ends, a source of injected waves having a greater maximum amplitude and a lower frequency than said carrier waves, injector input means for said injected waves, said injector input means having a first and a second end and a inidtap, output circuit means connected between said second end of said antiresonant input means and said midtap, a rst diode rectier having a first cathode and a first anode, a second diode rectier having a second cathode and a second anode, connection means for connecting said first y end of said antiresonant inputk means to both said first and second ends of said injector input means to said second end of said antiresonant input means.

5. A communication system including, a source of modulated carrier waves, antiresonant input means for said modulated carrier waves, said antiresonant input means having first and second ends, a source of injected waves having a greater maximum amplitude and a lower frequency than said carrier waves, untuned input means for said injected waves, said untuned input means having a first and a second end and a midtap, output circuit means connected between said second end of said antiresonant input means and said midtap, a rst diode rectifier having a first cathode and a rst anode, a second diode rectifier having a second cathode and a second anode, connection means for connecting said first end of said antiresonant input means to both said first anode and to -said second cathode, connection means for connecting said second anode and said first cathode, respectively, to said first and second ends of said untuned input means, and carrier wave bypass means for connecting liu said r'st and second ends of said untuned input means to said second end of said antiresonant input means, said output circuit means including a load impedance in parallel with the series combination of an inductive and a capacitive element, said series combination being resonant at the frequency of said injected waves.

I 6. A first and a second wave input circuit each having first and second ends, a rst and a second Wave source for energizing, respectively, said rst and second wave input circuits, said rst wave input circuit being antiresonant substantially at the frequency of said first wave source, said second wave input circuit being untuned, a series resonant output circuit being resonant substantially at the frequency of said second Wave source, a first and second diode, said rst diode being connected between said first end of said rst wave input circuit and said second end of said second wave input circuit, said second diode being connected between said first end of said rst wave input circuit and said first end of said second wave input circuit, said second wave input circuit having a midtap, and connection means for connecting said output circuit between said second end of said rst wave input circuit and said midtap.

DONALD L. HINGS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Name Date 1,376,679 Curtis May 3; 192i 1,418,285 Carson June 6, 1922 2,099,311 Nicholson Nov. 16, 1937 2,103,878 Thompson Dec. 28, 1937 2,166,995 Koch July 25, 1939 2,173,925 TuXen Sept. 26, 1939 2,214,929 Koschmeider Sept. 17, 1940 Y2,221,087 Foster Nov. 12, 1940 2,239,560 Herold Apr. 22, 1941 2,267,732 Hansell Dec. -30, 1941 2,363,288 Bell Nov. 21, 1944 2,441,598 Robertson May 18, 1948 2,446,188 Miller, Jr. Aug. 3, 1948 

